A while ago I released a Inkscape extension that can automatically generate patterns from shapes drawn, such as bag side panels. Not everyone has access to or uses Inkscape, so I’m working on bringing that key functionality to an online tool. Nearly instant patterns for backpacks, bike bags (frame bags, top tube bags etc) and more.

Work in progress! Might have some bugs. Test with a paper model or scrap fabric before committing to your expensive materials.

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Start Drawing!

Instructions:

Draw your shape by left mouse clicking on the canvas. Where you want a split in the pattern (new pattern piece) right click. Split points are shown with red markers.

Press enter or click the finalise button to complete the shape. Multiple PDF files will be generated containing your polygon and gusset with seam allowances calculated and tiled to fit your page size.

If you need to move the points, after finalising the shape you can click and drag the points to a better position. Click a line to add a new point, and click a point once to turn to a split point (red), twice to delete. You can also adjust the seam allowance and scaling.

Tape the edges of your printed paper together to build your pattern.

Made something cool? I’d love to see. Feel free to share your creations via the social links at the top of the page or the contact form.

Scaling:

You can choose how large you want the grid to be on the canvas, for easier snapping to the grid with more detailed pattern pieces.

The PDF is scaled based on how big each grid square is, which you specify in centimetres or inches. You can also select a segment (after the polygon is finished) to set to a known length for easy scaling.

Printing and Assembling:

Patterns must be printed at 100% or “Actual Size” or equivalent in your printer settings. Cut along the borders and tape the borders together.

Known quirks:

• Likely has bugs. Test whatever you generate with a paper model or scrap fabric before committing to fabric.
• You can draw whatever, but doesn’t mean you can sew it. For example, patterns with sharp inwards corners you will struggle to sew. Again, test on scraps before fully committing.
• Linear segments only currently. I might look into curved corners and beziers in the future. For now, just draw lots of points to simulate curves, and move the points if you need to adjust them.
• Wide gussets (wider than the paper width) aren’t tiled.

Changelog:

17 Nov 2024:

• Gusset piece dimensions listed in the PDF so you don’t have to print the pages
• One single PDF generated for the entire project

9 Nov 2024: Fixed bug when generating patterns with gussets larger than page width that caused freezing

6 Nov 2024: 3D view to help visualise your project